Honestly, Hyper-V can be sneakier than a Windows Update when it wants to be difficult. If you’ve checked all the BIOS/UEFI boxes and Hyper-V still acts like you’re speaking ancient Sumerian, peek at Windows Features again—sometimes it doesn’t enable “Windows Hypervisor Platform” or “Virtual Machine Platform” alongside main Hyper-V. Also, if you’ve got other virtualization software installed (VMware, VirtualBox, Docker Desktop, the kitchen sink…), they can fight over your virtualization extensions like toddlers over candy.
If all else fails, running Hyper-V’s built-in diagnostic:
Get-WindowsOptionalFeature -Online | Where-Object {$_.FeatureName -match "Hyper"}
…and checking the result might give a clue before you start looking for sacrificial goats. Sometimes, just uninstalling and re-enabling Hyper-V will do the trick—because sometimes, voodoo is the most technical solution of all.